Publications by authors named "Moamen Abdelaal"

Purpose: The role of adjuvant chemotherapy in rectal cancer patients downstaged to ypT0-2 N0 after neoadjuvant chemoradiotherapy (CRT), and surgery is still debated. This study investigates the impact of adjuvant chemotherapy on survival outcomes in this patient population.

Methods: This retrospective study analyzed hospital records of rectal cancer cases from Shefa Al Orman Cancer Hospital between January 2016 and December 2020, focusing on patients downstaged to ypT0-2 N0 after neoadjuvant CRT and surgery.

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Magnetic resonance (MR)-guided radiation therapy (RT) is enhancing head and neck cancer (HNC) treatment through superior soft tissue contrast and longitudinal imaging capabilities. However, manual tumor segmentation remains a significant challenge, spurring interest in artificial intelligence (AI)-driven automation. To accelerate innovation in this field, we present the Head and Neck Tumor Segmentation for MR-Guided Applications (HNTS-MRG) 2024 Challenge, a satellite event of the 27th International Conference on Medical Image Computing and Computer Assisted Intervention.

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Article Synopsis
  • The study investigates the impact of second look events (SLEs) for applicants in the 2023 Virtual Radiation Oncology residency match, assessing how they affect applicant and program evaluations.
  • A survey of applicants and program directors revealed that while many applicants were invited to SLEs, a significant number chose not to attend due to various reasons, including cost and logistics.
  • Program directors largely viewed SLEs as optional and assured applicants that participation would not impact their ranking decisions, though attending SLEs did appear to influence candidates' final rank order lists.
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Despite being rarely discussed, perinephric lymphatics are involved in many pathological and benign processes. The lymphatic system in the kidneys has a harmonious dynamic with ureteral and venous outflow, which can result in pathology when this dynamic is disturbed. Although limited by the small size of lymphatics, multiple established and emerging imaging techniques are available to visualize perinephric lymphatics.

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Article Synopsis
  • Adequate image registration of MRI scans is crucial in MR-guided adaptive radiotherapy for head and neck cancer, but geometric distortions pose a significant challenge.
  • * This study systematically evaluated multiple deformable image registration (DIR) methods, comparing commercial and open-source techniques, to align diffusion-weighted imaging (DWI) and T2-weighted (T2W) MRI images from the same session in 20 HNC patients.
  • * Results showed that ADMIRE and Elastix 23 methods outperformed others, significantly enhancing alignment accuracy for radiotherapy structures compared to non-registered images, with ADMIRE being notably faster and more effective.
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PET/CT images provide a rich data source for clinical prediction models in head and neck squamous cell carcinoma (HNSCC). Deep learning models often use images in an end-to-end fashion with clinical data or no additional input for predictions. However, in the context of HNSCC, the tumor region of interest may be an informative prior in the generation of improved prediction performance.

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Auto-segmentation of primary tumors in oropharyngeal cancer using PET/CT images is an unmet need that has the potential to improve radiation oncology workflows. In this study, we develop a series of deep learning models based on a 3D Residual Unet (ResUnet) architecture that can segment oropharyngeal tumors with high performance as demonstrated through internal and external validation of large-scale datasets (training size = 224 patients, testing size = 101 patients) as part of the 2021 HECKTOR Challenge. Specifically, we leverage ResUNet models with either 256 or 512 bottleneck layer channels that demonstrate internal validation (10-fold cross-validation) mean Dice similarity coefficient (DSC) up to 0.

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Determining progression-free survival (PFS) for head and neck squamous cell carcinoma (HNSCC) patients is a challenging but pertinent task that could help stratify patients for improved overall outcomes. PET/CT images provide a rich source of anatomical and metabolic data for potential clinical biomarkers that would inform treatment decisions and could help improve PFS. In this study, we participate in the 2021 HECKTOR Challenge to predict PFS in a large dataset of HNSCC PET/CT images using deep learning approaches.

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